Example embodiments relate generally to image sensors, and more particularly, example embodiments relate to a depth pixel included in a three-dimensional image sensor, the three-dimensional image sensor including a depth pixel, and a method of operating a depth pixel included in a three-dimensional image sensor.
An image sensor is a semiconductor device configured to convert an externally incident optical signal into an electrical signal which can used to derive image information corresponding to the optical signal. Recently, research has been directed towards the development of a three-dimensional image sensor which is capable of providing distance information as well as image information based on the optical signal. The three-dimensional image sensor may rely on distances between each of depth pixels and Time Of Flight (TOF) measurements to determine the distance of a subject. Here, TOF refers to a travel time of a laser pulse taken until the laser pulse returns to its origination through reflection after being irradiated onto the subject.